Dielectric ceramic composition and electronic device

ABSTRACT

The present invention relates to a dielectric ceramic composition comprising
     a main component expressed by a general formula:   

       (Ba 1-x-y Sr x Ca y ) m (Ti 1-z Zr z )O 3 ,     a first subcomponent comprising Mg oxide,   a second subcomponent comprising at least one kind of oxide selected from oxides of Mn and Cr,   a third subcomponent comprising R oxide (note R is selected at least one kind from Y, La Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Yb), and   a fourth subcomponent comprising an oxide including Si.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a dielectric ceramic composition,showing large absolute value of capacity temperature characteristicwithin a wide temperature range, and an electronic device, having adielectric layer constituted by said dielectric ceramic composition.

2. Description of the Related Art

VR (Voltage Regulator) is a system regulating voltage of DC/DCconverter, which drives CPU of notebook computer or so. Inductorresistance (Rdc) detects output voltage of VR, however, there was aproblem that an error arises in the detected value since Rdc varies dueto heat. Therefore, it is required to use properly within a widetemperature range. In the present state, NTC thermistor is used torevise the error of the detected value.

Further, capacitor is normally used for circuit of VR system. It isthought that, by using a capacitor showing large absolute value ofcapacity temperature characteristic, such as around −5000 ppm, saiderror can be revised. NTC thermistor is not required with this method,and its cost is reduced with advantage.

On the other hand, there is a demand for a capacitor showing smallabsolute value of capacity temperature characteristic, therefore, acapacitor showing large absolute value of capacity temperaturecharacteristic is scarcely informed. Note that the absolute value ofcapacity temperature characteristic of normal capacitor is at mostaround −1000 ppm/° C. or 350 ppm/° C.

Japanese Utility Model Publication No. H5-61998 describes a ceramiccapacitor using ceramic as dielectric wherein said ceramic showscapacity temperature characteristic of −1500 ppm/° C. to −5000 ppm/° C.and includes 20 to 95 wt % of SrTiO₃. However, dielectric layercomposition of ceramic capacitor described in Japanese Utility ModelPublication No. H5-61998 is partially unidentified and the othercomponents are totally unidentified. Further, said publication does notindicate temperature range wherein said capacitor temperaturecharacteristic is shown.

SUMMARY OF THE INVENTION

A purpose of the present invention, reflecting this situation, is toprovide a dielectric ceramic composition, showing large absolute valueof capacity temperature characteristic within a wide temperature range,and an electronic device, comprising a dielectric layer constituted bythe dielectric ceramic composition, by using predetermined compositionof a material to make the dielectric ceramic composition.

To attain the above object, the inventors engaged in intensive studiesand found that dielectric ceramic composition comprising a maincomponent expressed by a general formula:(Ba_(1-x-y)Sr_(x)Ca_(y))_(m)(Ti_(1-z)Zr_(z))O₃ and predeterminedsubcomponents show large value of capacity temperature characteristic(−7000 to −3000 ppm/° C.), which lead to a completion of the invention.

To attain the above object, a dielectric ceramic composition of theinvention comprises

-   a main component expressed by a general formula:

(Ba_(1-x-y)Sr_(x)Ca_(y))_(m)(Ti_(1-z)Zr_(z))O₃

-   a first subcomponent comprising Mg oxide,-   a second subcomponent comprising at least one kind of oxide selected    from oxides of Mn and Cr,-   a third subcomponent comprising R oxide (note R is selected at least    one kind from Y, La Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Yb), and-   a fourth subcomponent comprising an oxide including Si,-   wherein the general formula shows

0.20≦x≦0.40,

0≦y≦0.20,

0≦z≦0.30, and

0.950≦m≦1.050,

-   wherein ratios of the respective subcomponents with respect to 100    moles of said main component are-   the first subcomponent: 0.5 to 5 moles (in terms of element),-   the second subcomponent: 0.05 to 2 moles (in terms of element),-   the third subcomponent: 1 to 8 moles (in terms of element),-   the fourth subcomponent: 0.5 to 5 moles (in terms of an oxide or a    complex oxide), and-   within a temperature range of −25 to 105° C., a capacitance change    rate on the basis of capacitance at 25° C., with respect to slope    “a” of a line which shows capacity temperature characteristic on the    basis of capacitance at 25° C., is within −15 to +5% and said slope    “a” is −7000 to −3000 ppm/° C.

An electronic device according to the present invention is notparticularly limited as far as it comprises a dielectric layer composedof the dielectric ceramic composition as set forth in any one of theabove, and is, for example, a multilayer ceramic capacitor elementcomprising a capacitor element body, wherein dielectric layers andinternal electrode layers are alternately stacked. In the presentinvention, the conductive material included in the internal electrodelayer is not particularly limited and is, for example, Ni or a Ni alloys

According to the present invention, by determining compositions of maincomponent and subcomponent of dielectric ceramic composition, adielectric ceramic composition is characterized in that, within a widetemperature range (e.g. −25 to 105° C.), a capacitance change rate onthe basis of capacitance at 25° C., with respect to slope “a” of a linewhich shows capacity temperature characteristic on the basis ofcapacitance at 25° C., is within −15 to +5% and said slope “a” is −7000to −3000 ppm/° C.

Note that a capacitance change rate can be within a predetermined rangewith respect to any capacity temperature characteristic.

Accordingly, by using dielectric ceramic composition of the invention asdielectric layer of electric device, such as multilayer ceramiccapacitor, it is not required to revise an error of a detected value ofoutput voltage of VR caused by variation of Rdc without using NTCthermistor, for instance. Further, as long as dielectric ceramiccomposition determined in the present invention is used and absolutevalue of capacity temperature characteristic is required to be large,its application is not particularly limited.

Reasons for capability of obtaining these dielectric ceramiccompositions can be said as following.

An absolute value of capacity temperature characteristic of SrTiO₃ isrelatively large (−3300 ppm/° C.), however, a peak of specificpermittivity is shown at a considerably low temperature when compared toan ordinal temperature range (−25° C. to 105° C.). Note that said peakis shown near Curie temperature.

Therefore, by shifting this peak to a higher temperature, a greatinclination part at a higher temperature than the temperature shown bythe peak will be within an ordinal temperature range. In order to shiftthe peak to a higher temperature, it can be considered to substitute apart of SrTiO₃ to Ba. An element having a large ionic radius, such asBa, has an effect to shift the peak to a higher temperature.

According to the present invention, with the method described above, thepeak of specific permittivity is shifted to a higher temperature,therefore, the great inclination part at higher temperature than thetemperature shown by the peak will be within an ordinal temperaturerange (−25° C. to 105° C.). As a result, a dielectric ceramiccomposition showing larger absolute value of capacity temperaturecharacteristic within the above temperature range can be obtained.

Further, by comprising subcomponents, a great inclination, namely, alarge absolute value of capacity temperature characteristic can bemaintained while making capacitance change rate within a predeterminedrange.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, the present invention will be described based onembodiments shown in drawings.

FIG. 1 is a perspective view of a multilayer ceramic capacitor accordingto an embodiment of the present invention.

FIG. 2A is a graph showing a parallelogram surrounded by lines showingcapacitance change rate of −15 and +5%, respectively, with respect to aline showing capacity temperature characteristic on the basis ofcapacitance at 25° C. and having a slope of −5000 ppm/° C., and also bylines showing temperatures of −25° C. and 105° C., respectively.

FIG. 2B is a graph showing a parallelogram surrounded by lines showingcapacitance change rate of −15 and +5%, respectively, with respect to aline showing capacity temperature characteristic on the basis ofcapacitance at 25° C. and having a slope of −3000 ppm/° C., and also bylines showing temperatures of −25° C. and 105° C., respectively.

FIG. 3 is a graph showing capacity temperature characteristic on thebasis of capacitance at 25° C. of sample 1 of the present example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Multilayer Ceramic Capacitor 1

As shown in FIG. 1, multilayer ceramic capacitor 1 according to anembodiment of the present invention comprises a capacitor element body10, wherein dielectric layers 2 and internal electrode layers 3 arealternately stacked. On both end portions of the capacitor element body10, a pair of external electrode 4 is formed to be connectedrespectively to the internal electrode layers 3 alternately arrangedinside the element body 10. Formation of the capacitor element body 10is not particularly limited and generally rectangular parallelepiped.Further, size of the capacitor element body 10 is not particularlylimited and can be an appropriate size in accordance with the useobject.

The internal electrode layers 3 are stacked, so that each of the endsurfaces is alternately exposed to surfaces of the two facing endportions of the capacitor element body 10. The pair of externalelectrodes 4 are formed on both end portions of the capacitor elementbody 10 and connected to the exposed end surfaces of the alternatelyarranged internal electrode layers 3 so as to compose a capacitorcircuit.

Dielectric Layer 2

Dielectric layer 2 comprises dielectric ceramic composition of theinvention. Dielectric ceramic composition of the invention comprises amain component expressed by a general formula:

(Ba_(1-x-y)Sr_(x)Ca_(y))_(m)(Ti_(1-z)Zr_(z))O₃,

-   a first subcomponent comprising Mg oxide,-   a second subcomponent comprising at least one kind of oxide selected    from oxides of Mn and Cr,-   a third subcomponent comprising R oxide (note R is selected at least    one kind from Y, La Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Yb), and-   a fourth subcomponent comprising an oxide including Si.

As mentioned above, the main component of dielectric composition is acompound comprising perovskite structure expressed by a general formula:(Ba_(1-x-y)Sr_(x)Ca_(y))_(m)(Ti_(1-z)Zr_(z))O₃. Main component of thedielectric composition comprises perovskite structure wherein A siteconsists of Ba, Sr and Ca and B site consists of Ti and Zr.

In the above general formula, “x” indicates Sr ratio in A site,consisting of Ba, Sr and Ca, of main component. “x” is 0.20≦x≦0.40,preferably 0.25≦x≦0.35. When “x” is too small, dielectric loss andcapacitance change rate tend to deteriorate, while when too large,specific permittivity reduces and capacitance change rate at a lowertemperature tends to deteriorate.

In the above general formula, “y” indicates Ca ratio in A site. “y” is0≦y≦0.20, preferably 0≦y≦0.1, more preferably y=0 . When “y” is toolarge, capacitance change rate is flattened and tends to be without apreferable range of the invention.

In the above general formula, “z” indicates Zr ratio in B site,consisting of Ti and Zr, of main component. “z”, is 0.20≦z≦0.30,preferably 0≦z≦0.1, more preferably z=0. When “z” is too large, specificpermittivity reduces and capacitance change rate is flattened and tendsto be without a preferable range of the invention.

Note that when y=0 and z=0, the above general formula is expressed by(Ba_(1-x)Sr_(x))_(m)TiO₃ wherein “x” indicates a ratio of Ba and Sr and“x” is preferably within the above mentioned range.

In the above general formula, “m” indicates mole ratio of A site and Bsite. “m” is 0.950 to 1.050, preferably 0.98 to 1.02.

Content of the first subcomponent (Mg oxide) with respect to 100 molesof the main component is 0.5 to 5 moles, preferably 1 to 4 moles, morepreferably 1.5 to 3 moles in terms of an element. When content of thefirst subcomponent is too small, capacitance change rate deterioratesand high temperature accelerated lifetime tends to be deteriorated,while when too large, it tends not to sinter densely.

Content of the second subcomponent (oxides of Mn and Cr) with respect to100 moles of the main component is 0.05 to 2 moles, preferably 0.1 to 1mole, more preferably 0.1 to 0.5 mole in terms of an element. Whencontent of the second subcomponent is too small, insulation resistancetends to deteriorate while when too large, high temperature acceleratedlifetime tends to be deteriorated.

The second subcomponent comprises at least one kind of oxide selectedfrom oxides of Mn and Cr. Considering insulation resistance, Mn ispreferable.

Content of the third subcomponent (R oxide) with respect to 100 moles ofthe main component is 1 to 8 moles, preferably 2 to 7 moles, morepreferably 3 to 5 moles in terms of an element. When content of thethird subcomponent is too small, high temperature accelerated lifetimetends to be deteriorated, while when too large, it tends not to sinterdensely.

R in the third subcomponent is selected at least one kind from Y, La Ce,Pr, Nd, Sm, Gd, Tb, Dy, Ho and Yb. Considering high temperatureaccelerated lifetime and capacitance change rate, Tb and Y arepreferable and Y is more preferable.

Content of the fourth subcomponent (oxide including Si) with respect to100 moles of the main component is 0.5 to 5 moles, preferably 1 to 4.5moles, more preferably 2 to 3.5 moles in terms of the oxide. Whencontent of the fourth subcomponent is too small, capacitance change ratetends to deteriorate while when too large, it tends not to sinterdensely.

The fourth subcomponent of oxide including Si may be a complex or asimple oxide, however, complex oxide is preferable and (Ba,Ca)_(n)SiO_(2+n) (note that n=0.8 to 1.2) is more preferable. Further,“n” in (Ba, Ca)_(n)SiO_(2+n) is preferably 0 to 2 and more preferably0.8 to 1.2. When “n” is too small, it tends to react with bariumtitanate included in a main component and deteriorate dielectriccharacteristic, while when too large, melting point tends to be higherand degree of sintering tends to be deteriorated. Note that ratio of Baand Ca included in the fourth subcomponent is optional and only eitherone may be included.

Dielectric ceramic composition of the invention is preferable to furtherinclude fifth subcomponent. Content of the fifth subcomponent withrespect to 100 moles of the main component is 0 to 0.2 mole, preferably0.01 to 0.07 mole, more preferably 0.02 to 0.06 moles in terms of eachelement. When content of the fifth subcomponent is too large, insulationresistance tends to be deteriorated.

The fifth subcomponent comprises at least one kind of oxide selectedfrom oxides of V, Mo, W, Ta and Nb. Considering high temperatureaccelerated lifetime, it is preferably Nb and V, and more preferably V.

In the present specification, each oxide or complex oxide comprisingeach component are expressed by stoichiometric composition but oxidizedstate of each oxide or complex oxide can be out of this range. Note thatthe above ratio of each component, except for the fourth subcomponent,is obtained by converting metal amount included in an oxide of eachcomponent to an element. The fourth subcomponent is obtained byconverting the same to oxide or complex oxide.

Note that an average particle diameter of sintered body obtained bysintering the above main component and subcomponents is preferably 0.2to 1.5 μm, more preferably 0.2 to 0.8 μm.

Thickness of dielectric layer 2 is not particularly limited and can bean appropriate thickness in accordance with the use of multilayerceramic capacitor 1.

Dielectric ceramic composition of the invention is characterized inthat, within a temperature range of −25 to 105° C., a capacitance changerate on the basis of capacitance at 25° C., with respect to slope “a” ofa line which shows capacity temperature characteristic on the basis ofcapacitance at 25° C., is within −15 to +5%, preferably −10 to 0%.

Said slope “a” is −7000 to −3000 ppm/° C., preferably −6000 to −4000ppm/° C., more preferably −5500 to −4500 ppm/° C.

As shown in FIGS. 2A and 2B, “−15 to +5% with respect to slope “a” of aline which shows capacity temperature characteristic on the basis ofcapacitance at 25° C. at a temperature range of −25 to 105° C.”determines an area surrounded by a parallelogram comprising two parallellines representing said −15% and +5%, respectively, and the other twoparallel lines representing −25° C. and 105° C., respectively, shown ina graph indicated by x-axis of temperature and y-axis of capacitancechange rate. Namely, when the slope “a” is −5000 ppm/° C., said area isthe parallelogram shown in FIG. 2A, while when −3000 ppm/° C., theparallelogram shown in FIG. 2B.

Internal Electrode 3

Base metal included in internal electrode 3 is not particularly limitedand, since composite material of dielectric layer 2 showreduction-resistance, relatively low cost base metals can be used. Asthe base metal to be used as the conductive material, Ni or a Ni alloyis preferable. As the Ni alloy, an alloy of one or more kinds selectedfrom Mn, Cr, Co and Al with Ni is preferable, and a content of Ni in thealloy is preferably 95 wt % or more. Note that the Ni or the Ni alloymay contain various trace components, such as P, by not more than 0.1 wt% or so. Further, internal electrode 3 can be made by using commerciallyavailable electrode paste. A thickness of the internal electrode layer 3in the present embodiment can suitably determined in accordance with itsuse.

External Electrode 4

Conducting material included in external electrode 4 is not particularlylimited and a low cost material such as Ni, Cu and their alloys can beused in the invention. A thickness of the external electrode 4 cansuitably determined in accordance with its use.

Manufacturing Method of Multilayer Ceramic Capacitor 1

Multilayer ceramic capacitor 1 of the present embodiment is, as is thesame with conventional multilayer ceramic capacitor, manufactured bymaking green chip by normal printing method or sheet method using paste,firing the same, and then, printing or transferring external electrodeand firing the same. Said manufacturing method will be concretelydescribed below.

First, dielectric material (dielectric ceramic composition powder)included in dielectric layer paste is prepared; paste the same, and thendielectric layer paste is prepared. Said dielectric layer paste can bean organic paste, wherein dielectric material and organic vehicle arekneaded, or an aqueous paste.

As dielectric material, oxides of each component mentioned above, theirmixtures and complex oxides can be used. Further, a mixture suitablyselected from each compound that become the above mentioned oxides orcomplex oxides after firing, such as carbonates, oxalates, nitrates,hydroxides and organic metal compounds can be used. Content of eachcompound in dielectric material is determined in order to obtain theabove dielectric ceramic composition after firing.

Further, as at least a part of material in the above each component,each oxide, complex oxides, and compounds that become each oxide orcomplex oxides after firing can be used as they are, or as roastedpowder obtained by preliminary firing the same.

An average particle diameter of material of main component(Ba_(1-x-y)Sr_(x)Ca_(y))_(m)(Ti_(1-z)Zr_(z))O₃ in dielectric material ispreferably 0.15 to 0.7 μm, more preferably 0.2 to 0.5 μm. When theaverage particle diameter of material is smaller than 0.15 μm, theaverage particle diameter of sintered body becomes 0.2 μm or less, thatlowers its specific permittivity and tends to deteriorate capacitancechange rate at higher temperature. Further, when the average particlediameter of material is larger than 0.7 μm, the average particlediameter of sintered body becomes 1.5 μm or more that deteriorates hightemperature accelerated lifetime and capacitance change rate at lowertemperature.

The organic vehicle is a binder dissolved in an organic solvent. Thebinder used for the organic vehicle is not particularly limited and maybe suitably selected from ethyl cellulose, polyvinyl butyral, and otherusual various types of binders. Further, the organic solvent used isalso not particularly limited and may be suitably selected fromterpineol, butyl carbitol, acetone, toluene, and other various types oforganic solvents in accordance with the method of use, such as printingmethod and sheet method.

When dielectric layer paste is an aqueous paste, an aqueous vehicle,wherein water-soluble binder, dispersant, etc. are solved in water, anddielectric material are kneaded. Water-soluble binder used for theaqueous vehicle is not particularly limited and polyvinyl alcohol,cellulose, and a water-soluble acrylic resin, etc. may be used.

An internal electrode layer paste is fabricated by kneading theconductive material composed of the above variety of conductive metalsand alloys, or a variety of oxides, organic metal compounds andresonates, etc. to be the above conductive materials after firing, withthe above organic vehicle.

An external electrode paste is fabricated in the same way as that of theabove internal electrode layer paste.

A content of the organic vehicle in each paste is not particularlylimited and may be a normal content of, for example, 1 to 5 wt % or soof the binder and 10 to 50 wt % or so of the solvent. Also, additivesselected from a variety of dispersants, plasticizers, dielectrics andinsulators, etc. may be included in each paste in accordance with need.Total of said content is preferably 10 wt % or less.

When using the printing method, the dielectric layer paste and internalelectrode layer paste are printed on a PET or other substrate, stacked,and then cut to predetermined forms which are then peeled off from thesubstrate to obtain green chips.

Further, when using the sheet method, the dielectric layer paste is usedto form a green sheet, this is printed with the internal electrode layerpaste, and then this is stacked to form a green chip.

Before firing, the green chip is treated to remove the binder. Theconditions of treatment for removing the binder are; temperature raisingrate of preferably 5 to 300° C./hour, holding temperature of preferably180 to 400° C. and temperature holding time of preferably 0.5 to 24hours. Further, firing atmosphere is air or reduced atmosphere.

Atmosphere when firing green chip can be an appropriate atmosphere inaccordance with conductive material included in internal electrode layerpaste, however, when using Ni or Ni alloy or other base metal as theconductive material, the oxygen partial pressure in the firingatmosphere is preferably 10⁻¹⁴ to 10⁻¹⁰ MPa. If the oxygen partialpressure is less than that range, the conductive material of theinternal electrode layers will abnormally sinter and will end up causingdisconnection in some. Further, if the oxygen partial pressure exceedsthat range, the internal electrode layers tend to oxidize.

Further, the holding temperature at the time of firing is preferably1000 to 1400° C. If the holding temperature is less than the range, thedensification becomes insufficient, while if over that range, theinternal electrode layers will abnormally sinter causing electrodedisconnection, the internal electrode layer materials will diffuseresulting in deterioration of the capacity temperature characteristic,or the dielectric ceramic composition will easily be reduced.

As the other firing conditions, the rate of temperature rise ispreferably 50 to 500° C./hour, the temperature holding time ispreferably 0.5 to 8 hours, and the cooling rate is preferably 50 to 500°C./hour. Further, the firing atmosphere is preferably made a reducingatmosphere.

When firing in a reducing atmosphere, it is preferable that thecapacitor element body is annealed. The annealing is treatment forreoxidizing the dielectric layer. This enables the IR life to beremarkably lengthened, so the reliability is improved.

The oxygen partial pressure in the annealing atmosphere is preferably10⁻⁹ to 10⁻⁵ MPa.

The holding temperature at the time of annealing is preferably 1100° C.or less, particularly 500 to 1100° C.

As other annealing conditions, the temperature holding time ispreferably 0 to 20 hours.

To wet the N₂ gas or a mixed gas etc. in the above treatment to removethe binder, firing, and annealing, for example a wetter etc. may beused. In this case, the water temperature is preferably 5 to 75° C. orso. The treatment to remove the binder, firing, and annealing may beperformed consecutively or independently.

The thus obtained capacitor element body is end polished and fired withthe external electrode paste to form the external electrodes 4. Further,in accordance with need, the external electrodes 4 are plated etc. toform covering layers.

The thus produced multilayer ceramic capacitor of the present embodimentis mounted on a printed circuit board by soldering etc. and used forvarious types of electronic equipments.

An embodiment of the present invention was explained above, but thepresent invention is not limited to the embodiment and may be variouslyembodied within the scope of the present invention.

For example, in the above embodiment, a multilayer ceramic capacitor wasexplained as an example of an electronic device according to the presentinvention, but the electronic device according to the present inventionis not limited to a multilayer ceramic capacitor and may be any as faras it includes a dielectric layer having the above composition.

EXAMPLES

Below, the present invention will be explained based on further detailedexamples; however, the present invention is not limited to the examples.

Example 1

First, a multilayer ceramic capacitor of sample 1 in Table 1 isdescribed.

(Ba_(1-x-y)Sr_(x)Ca_(y))_(m)(Ti_(1-z)Zr_(z))O₃, MgCO₃, MnO, Y₂O₃,BaCaSiO₃ and V₂O₅ having an average particle diameter of 0.351 μm wereprepared, mixed by a ball mill, the obtained mixed powder waspreliminary fired at 1200° C., and a preliminary fired powder having anaverage particle diameter of 0.4 μm was obtained. Next, the obtainedpreliminary fired powder was wet pulverized by a ball mill for 15 hours,and then dried to obtain dielectric material. Note that, after firing,MgCO₃ will be included in dielectric ceramic composition as MgO.

Composition of the main component and contents of each subcomponent areshown in sample 1 of Table 1. Contents of each subcomponent, except forthe fourth subcomponent, are the contents of element with respect to 100moles of a main component(Ba_(1-x-y)Sr_(x)Ca_(y))_(m)(Ti_(1-z)Zr_(z))O₃. Content of the fourthsubcomponent, with respect to 100 moles of the main component, is acontent in terms of a complex oxide or each oxide. Further, in thepresent embodiment, (Ba_(1-x-y)Sr_(x)Ca_(y))_(m)(Ti_(1-z)Zr_(z))O₃wherein m=1.000 was used.

Next, 100 parts by weight of the obtained dielectric material, 10 partsby weight of polyvinyl butyral, 5 parts by weight of dibutyl phthalate(DBP) as plasticizer, and 100 parts by weight of alcohol as solvent wereball milled and pasted to obtain dielectric layer paste.

Next, 45 parts by weight of Ni particles, 52 parts by weight ofterpineol and 3 parts by weight of ethyl cellulose were kneaded by atriple roll to be a slurry to obtain internal electrode layer paste.

By using the obtained dielectric layer paste, a green sheet having athickness of 10 μm after drying was formed on a PET film. Next, by usingthe internal electrode layer paste, electrode layer was printed on thegreen sheet by a predetermined pattern and then, the green sheet wasremoved from the PET film to obtain green sheet having electrode layer.Next, a plurality of green sheets having electrode layer were stacked,bonded with a pressure to obtain green multilayer body. The greenmultilayer body was cut into a predetermined size to obtain green chip.

Next, the obtained green chip was subjected to binder removalprocessing, firing and annealing on the conditions below so as to obtaina multilayer ceramic fired body.

The binder removal processing condition was a temperature raising rateof 25° C./hour, holding temperature of 250° C., temperature holding timeof 8 hours and atmosphere of air.

The firing condition was a temperature raising rate of 200° C./hour,holding temperature of 1300° C., temperature holding time of 2 hours,temperature cooling rate of 200° C./hour and atmosphere of a wet mixedgas of N₂ and H₂ (oxygen pressure of 10⁻¹² MPa).

The annealing condition was a temperature raising rate of 200° C./hour,holding temperature of 1100° C., temperature holding time of 2 hours,temperature cooling rate of 200° C./hour and atmosphere of a wet N₂ gas(oxygen pressure of 10⁻⁷ MPa).

Next, after polishing an end surface of the obtained multilayer ceramicsintered body by sand blast, In—Ga was applied as external electrodesand sample of the multilayer ceramic capacitor shown in FIG. 1 wasobtained. A size of the obtained capacitor sample was 3.2 mm×1.6 mm×3.2mm, a thickness of dielectric layer was 8 μm, a thickness of internalelectroe layer was 1.5 μm and the number of dielectric layers betweeninternal electrode layers was 4.

A specific permittivity (εs), dielectric loss (tan δ), insulationresistance (IR), capacitance change rate, high temperature acceleratedlifetime (HALT) and average particle diameter in sintered body of thusobtained each capacitor sample were measured by the methods shown below.

Specific Permittivity εs

Specific permittivity εs was calculated from a capacitance of theobtained capacitor sample measured at a reference temperature of 25° C.with a digital LCR meter (4274A made by YHP) under a condition of afrequency of 1 kHz and an input signal level (measurement voltage) of1.0 Vrms. Higher specific permittivity is preferable and those exhibited1000 or higher were determined good in the present embodiment. Theresults are shown in Table 2.

Dielectric Loss (tan δ)

Dielectric loss (tan δ) was measured from the obtained capacitor sampleat a reference temperature of 25° C. with a digital LCR meter (4274Amade by YHP) under a condition of a frequency of 1 kHz and an inputsignal level (measurement voltage) of 1.0 Vrms. Lower dielectric loss ispreferable and those exhibited 3% or less were determined good in thepresent example. The results are shown in Table 2.

Insulation Resistance (IR)

Insulation resistance (IR) was measured when a capacitor sample wasimpressed with DC100V for 60 seconds at 25° C. by insulation resistancemeter (R8340 made by Advantest). Higher insulation resistance ispreferable and those exhibited 1×10¹⁰ MΩ or higher were determined goodin the present example. The results are shown in Table 2.

Capacitance Change Rate

Capacitance was measured in a temperature range of −25 to 105° C. with adigital LCR meter (4284A made by YHP) under a condition of a frequencyof 1 kHz and an input signal level (measured voltage) of 1 Vrms. Then,capacitance change rate (unit is %) was calculated at −25° C. and 105°C., with respect to the capacitance at reference temperature of 25° C.Those within −15% to +5% were determined good in the present example.The results are shown in Table 2.

High Temperature Accelerated Lifetime (HALT)

For the capacitor samples, the life time was measured while applying thedirect voltage under the electric field of 40 V/μm at 200° C., andthereby the high temperature accelerated lifetime (HALT) was evaluated.In the present example, the lifetime was defined as the time from thebeginning of the voltage application until the insulation resistancedrops by one digit. Also, this high temperature accelerated lifetimeevaluation was performed to 10 capacitor samples. In the presentexample, 3.1 hours or longer was determined good. The results are shownin Table 2.

Average Particle Diameter of Sintered Body

In order to measure an average particle diameter of dielectric particlesin sintered body, the obtained capacitor samples were cut at a surfacevertical to internal electrode, then said cut surface was polished.After chemical etching the polished surface, the surface was observedwith a scanning electron microscope (SEM) and an average particlediameter was measured based on the code method by assuming that theparticles have spherical shapes. The results are shown in Table 2.

Example 2

Other than determining average particle diameter of material of maincomponent, composition of main component, contents of subcomponent withrespect to 100 moles of the main component, and kinds of the third andfourth subcomponents described in tables 1 and 3, capacitor samples werefabricated in the same way as that in sample 1 and the same evaluationas that in sample 1 was made (samples 2 to 48). Results are shown intables 2 and 4.

Table 1

TABLE 1 contents of subcomponents with respect to 100 moles of main ancomponent [mol] average The The third The fifth particle compositions ofThe first second subcom- The fourth subcom- diameter main component sub-subcom- ponent subcomponent ponent (V, of main(Ba_(1−x−y)Sr_(x)Ca_(y))_(m)(Ti_(1−z)Zr_(z))O₃ component ponent (rarekind of the Mo, W, item component x y z m (Mg) (Mn, Cr) earths) fourthsub- Ta, Nb) No. range [μm] 0.20~0.40 0~0.20 0~0.30 0.950~1.050 0.5~5 A0.05~2 R 1~8 component 0.5~5 D 0~0.2  1 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 4BaCaSiO₃ 3 V 0.06  2* 0.35 0.10 0 0 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06 3 0.35 0.20 0 0 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06  4 0.35 0.40 0 01.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06  5* 0.35 0.50 0 0 1.000 2 Mn 0.2 Y4 BaCaSiO₃ 3 V 0.06  6* 0.35 0.21 0.30 0 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V0.06  7 0.35 0.24 0.20 0 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06  8 0.350.25 0.15 0.20 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06  9 0.35 0.30 0 0.301.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06  10* 0.35 0.30 0 0.40 1.000 2 Mn0.2 Y 4 BaCaSiO₃ 3 V 0.06  11* 0.35 0.30 0 0 0.900 2 Mn 0.2 Y 4 BaCaSiO₃3 V 0.06 12 0.35 0.30 0 0 0.950 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06 13 0.350.30 0 0 1.050 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06  14* 0.35 0.30 0 0 1.100 2Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06  15* 0.35 0.30 0 0 1.000 0.3 Mn 0.2 Y 4BaCaSiO₃ 3 V 0.06 16 0.35 0.30 0 0 1.000 0.5 Mn 0.2 Y 4 BaCaSiO₃ 3 V0.06 17 0.35 0.30 0 0 1.000 5 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06  18* 0.350.30 0 0 1.000 8 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06  19* 0.35 0.30 0 0 1.000 2Mn 0.02 Y 4 BaCaSiO₃ 3 V 0.06 20 0.35 0.30 0 0 1.000 2 Mn 0.05 Y 4BaCaSiO₃ 3 V 0.06 21 0.35 0.30 0 0 1.000 2 Mn 2 Y 4 BaCaSiO₃ 3 V 0.06 22* 0.35 0.30 0 0 1.000 2 Mn 3 Y 4 BaCaSiO₃ 3 V 0.06 23 0.35 0.30 0 01.000 2 Cr 0.2 Y 4 BaCaSiO₃ 3 V 0.06 “*” indicates a sample without therange of the invention “**” indicates a sample without the range ofclaim 3 of the invention Italicized numerical values are without therange of the invention.

Table 2

TABLE 2 an high average capacity temperature particle initialcharacteristic temperature accelerated diameter specific dielectricinsulation change life time of permittivity loss resistance rate (HALT)sintered (εs) (tan δ) [%] (R) [MΩ] (Tc) [%] [n] Decision item body 10003 1.0E10 −25° C. 105° C. 3.1 good or No. range [μm] or more or less ormore −15%~+5% −15%~+5% or more bad  1 0.4 1400 0.89 5.70E+11 −10% −8% 48good  2* 0.5 3500 3.20 1.30E+11 +62% −20% 4.5 bad  3 0.4 1800 1.605.00E+11 −5% −12% 45 good  4 0.6 1140 0.45 6.00E+11 4% −5% 14 good  5*0.4 800 0.30 6.10E+11 +38% −2% 7.2 bad  6* 0.6 1010 0.92 2.50E+11 −18%8% 4.9 bad  7 0.5 1260 1.19 4.30E+11 −5% −4% 21 good  8 0.4 1150 1.028.90E+11 −12% −2% 28 good  9 0.4 1110 0.99 9.50E+11 −9% 1% 30 good  10*0.4 950 0.67 3.50E+11 −43% 26% 38 bad  11* — Do Not Sinter Densely bad12 0.7 1370 0.81 6.50E+11 −12% −6% 30 good 13 0.4 1420 0.95 4.20E+11 −8%−10% 25 good  14* — Do Not Sinter Densely bad  15* 2.3 2800 2.703.30E+10 +29% +12% 0.24 bad 16 0.7 1550 0.92 7.00E+11 −13% −12% 60 good17 0.4 1050 1.30 4.40E+11 −4% 1% 21 good  18* — Do Not Sinter Denselybad  19* 0.4 1510 2.30 8.20E+08 −12% −7% 3.3 bad 20 0.4 1400 1.801.20E+11 −11% −5% 46 good 21 0.5 1380 1.40 9.80E+11 −7% −6% 7.6 good 22* 0.6 1320 1.20 5.20E+11 −6% −6% 0.12 bad 23 0.4 1390 0.91 6.20E+11−11% −7% 18 good “*” indicates a sample without the range of theinvention “**” indicates a sample without the range of claim 3 of theinvention Italicized numerical values are without the range of theinvention.

Table 3

TABLE 3 contents of subcomponents with respect to 100 moles of main ancomponent [mol] average The The third The fifth particle compositions ofThe first second subcom- The fourth subcom- diameter main component sub-subcom- ponent subcomponent ponent (V, of main(Ba_(1−x−y)Sr_(x)Ca_(y))_(m)(Ti_(1−z)Zr_(z))O₃ component ponent (rarekind of the Mo, W, item component x y z m (Mg) (Mn, Cr) earths) fourthsub- Ta, Nb) No. range [μm] 0.20~0.40 0~0.20 0~0.30 0.950~1.050 0.5~5 A0.05~2 R 1~8 component 0.5~5 D 0~0.2  24* 0.35 0.30 0 0 1.000 2 Mn 0.2 Y0.2 BaCaSiO₃ 3 V 0.06 25 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 1 BaCaSiO₃ 3 V0.06 26 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 8 BaCaSiO₃ 3 V 0.06  27* 0.350.30 0 0 1.000 2 Mn 0.2 Y 12 BaCaSiO₃ 3 V 0.06 28 0.35 0.30 0 0 1.000 2Mn 0.2 La 4 BaCaSiO₃ 3 V 0.06 29 0.35 0.30 0 0 1.000 2 Mn 0.2 Ce 4BaCaSiO₃ 3 V 0.06 30 0.35 0.30 0 0 1.000 2 Mn 0.2 Pr 4 BaCaSiO₃ 3 V 0.0631 0.35 0.30 0 0 1.000 2 Mn 0.2 Nd 4 BaCaSiO₃ 3 V 0.06 32 0.35 0.30 0 01.000 2 Mn 0.2 Sm 4 BaCaSiO₃ 3 V 0.06 33 0.35 0.30 0 0 1.000 2 Mn 0.2 Gd4 BaCaSiO₃ 3 V 0.06 34 0.35 0.30 0 0 1.000 2 Mn 0.2 Tb 4 BaCaSiO₃ 3 V0.06 35 0.35 0.30 0 0 1.000 2 Mn 0.2 Dy 4 BaCaSiO₃ 3 V 0.06 36 0.35 0.300 0 1.000 2 Mn 0.2 Ho 4 BaCaSiO₃ 3 V 0.06 37 0.35 0.30 0 0 1.000 2 Mn0.2 Yb 4 BaCaSiO₃ 3 V 0.06  38* 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 4BaCaSiO₃ 0.2 V 0.06 39 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 0.5 V0.06 40 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 5 V 0.06  41* 0.350.30 0 0 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 8 V 0.06 42 0.35 0.30 0 0 1.000 2Mn 0.2 Y 4 BaSiO₃ 3 V 0.06 43 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 4 CaSiO₃ 3V 0.06 44 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 4 SiO₃ 3 V 0.06 45 0.35 0.30 00 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0 46 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 4BaCaSiO₃ 3 V 0.2  47** 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.348 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 Mo 0.06 49 0.35 0.30 0 01.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 W 0.06 50 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 4BaCaSiO₃ 3 Ta 0.06 51 0.35 0.30 0 0 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 Nb0.06 52 0.15 0.30 0 0 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06 53 0.7 0.30 00 1.000 2 Mn 0.2 Y 4 BaCaSiO₃ 3 V 0.06 “*” indicates a sample withoutthe range of the invention “**” indicates a sample without the range ofclaim 3 of the invention Italicized numerical values are without therange of the invention.

Table 4

TABLE 4 an high average capacity temperature particle initialcharacteristic temperature accelerated diameter specific dielectricinsulation change life time of permittivity loss resistance rate (HALT)sintered (εs) (tan δ) [%] (R) [MΩ] (Tc) [%] [n] Decision item body 10003 1.0E10 −25° C. 105° C. 3.1 good or No. range [μm] or more or less ormore −15%~+5% −15%~+5% or more bad  24* 0.8 1480 0.92 5.50E+11 −14% −12%0.21 bad 25 0.4 1510 0.75 6.70E+11 −12% −1% 18 good 26 0.4 1240 1.909.60E+10 −5% −2% 44 good  27* — Do Not Sinter Densely bad 28 1.1 19501.30 2.30E+10 −14% 4% 4.5 good 29 0.8 1840 1.24 4.50E+10 −13% 2% 8.9good 30 0.7 1600 1.14 7.80E+10 −13% 1% 19 good 31 0.6 1590 1.10 9.80E+10−12% −5% 25 good 32 0.6 1540 1.02 1.10E+11 −12% −9% 36 good 33 0.4 14000.92 1.10E+11 −12% −14% 46 good 34 0.4 1400 0.75 6.10E+11 −11% −13% 52good 35 0.4 1400 0.95 4.80E+11 −10% −10% 32 good 36 0.4 1400 0.984.80E+11 −10% −11% 28 good 37  0.35 1380 1.03 3.40E+11 −9% −1% 9.2 good 38* 0.9 2050 1.90 2.00E+11 +22% +6% 4.1 bad 39 0.4 1550 0.91 1.20E+11−8% −12% 20 good 40 0.4 1210 1.10 8.10E+10 −7% −6% 16 good  41* — Do NotSinter Densely bad 42 0.4 1450 1.32 4.30E+11 −11% −13% 12 good 43 0.41390 0.77 9.20E+10 −10% −9% 18 good 44 0.5 1410 0.49 8.90E+11 −14% −14%32 good 45 0.5 1400 0.79 9.50E+11 −9% −8% 11 good 46 0.4 1400 0.842.30E+10 −10% −7% 72 good  47** 0.4 1370 0.94 4.70E+09 −11% −8% 88 bad48 0.3 1280 0.77 8.40E+10 −10% −9% 24 good 49 0.3 1290 0.81 9.10E+10 −9%−10% 22 good 50 0.4 1380 0.92 4.20E+11 −12% −7% 29 good 51 0.4 1410 0.894.80E+11 −11% −8% 39 good 52 0.2 1200 0.75 6.20E+11 −8% −3% 84 good 531.5 1500 1.10 5.20E+11 −14% −10% 10 good “*” indicates a sample withoutthe range of the invention “**” indicates a sample without the range ofclaim 3 of the invention Italicized numerical values are without therange of the invention.x (ratio of Sr in A Site) Effect (Samples 1 to 5)

As is shown in tables 1 and 2, contents of not only x but y, z, m andcontents of subcomponents with respect to main component in samples 1, 3and 4 were within the range of the present invention. These samples 1, 3and 4 show preferable values of dielectric loss and capacitance changerate, respectively, when compared to a sample (e.g. sample 2) comprisingless contents of x than the range of the present invention. Further,samples 1, 3 and 4 show preferable values of specific permittivity andcapacitance change rate at a low temperature, respectively, whencompared to a sample (e.g. sample 5) comprising more contents of x thanthe range of the present invention.

y (Ratio of Ca in A Site) Effect (Samples 1 and 6 to 8)

As is shown in tables 1 and 2, contents of not only y but x, z, m andcontents of subcomponents with respect to main component in samples 1, 7and 8 were within the range of the present invention. These samples 1, 7and 8 show preferable values of specific permittivity and capacitancechange rate, respectively, when compared to a sample (e.g. sample 6)comprising more contents of y than the range of the present invention.

z (Ratio of Zr in B Site) Effect (Samples 1 and 8 to 10)

As is shown in tables 1 and 2, contents of not only z but x, y, m andcontents of subcomponents with respect to main component in samples 1, 8and 9 were within the range of the present invention. These samples 1, 8and 9 show preferable values of specific permittivity and capacitancechange rate, respectively, when compared to a sample (e.g. sample 10)comprising more contents of z than the range of the present invention.

m (Ratio of A site and B Site) Effect (Samples 1 and 11 to 14)

As is shown in tables 1 and 2, not only m but contents of subcomponentswith respect to main component in samples 1, 12 and 13 were within therange of the present invention. These samples 1, 12 and 13 show densersintering when compared to a sample (e.g. samples 11 and 14) wherein “m”is without the range of the invention.

The First Subcomponent Effect (Samples 1 and 15 to 18)

As is shown in tables 1 and 2, contents of not only the firstsubcomponent (MgO) with respect to 100 moles of the main component butcomposition of main component and the other subcomponents in samples 1,16 and 17 are within the range of the invention. These samples 1, 16 and17 show preferable values of capacitance change rate and hightemperature accelerated lifetime, respectively, when compared to asample (e.g. sample 15) comprising less MgO content than the range ofthe present invention. Further, samples 1, 16 and 17 show densersintering when compared to a sample (e.g. sample 18) comprising morecontents of the first subcomponent than the range of the presentinvention.

The Second Subcomponent Effect (Samples 1 and 19 to 23)

As is shown in tables 1 and 2, a content of not only the secondsubcomponent (MnO) with respect to 100 moles of the main component butcomposition of main component and the other subcomponents in samples 1,20 and 21 are within the range of the invention. These samples 1, 20 and21 show preferable values of insulation resistance, when compared to asample (e.g. sample 19) comprising less content of the secondsubcomponent than the range of the present invention. Further, samples1, 20 and 21 show preferable temperature accelerated lifetime, whencompared to a sample (e.g. sample 22) comprising more contents of thesecond subcomponent than the range of the present invention.

Also, by referring to sample 23, when Cr was used instead of Mn as thesecond subcomponent, it was observed that the same effects as that of Mncan be obtained.

The Third Subcomponent (R Oxide) Effect (Samples 1 and 24 to 37)

As is shown in tables 3 and 4, not only a content of the thirdsubcomponent (Y₂O₃) with respect to 100 moles of the main component butcomposition of the main component and contents of the othersubcomponents in samples 1, 25 and 26 are within the range of theinvention. These samples 1, 25 and 26 show preferable value of hightemperature accelerated lifetime, when compared to a sample (e.g. sample24) comprising less content of the third subcomponent than the range ofthe present invention. Further, samples 1, 25 and 26 show densersintering when compared to a sample (e.g. sample 18) comprising morecontent of the second subcomponent than the range of the presentinvention.

Also, by referring to samples 28 to 37, when La Ce, Pr, Nd, Sm, Gd, Tb,Dy, Ho and Yb were used instead of Y as R, it can be observed that thesame effects as that of Y can be obtained.

The Fourth Subcomponent (Oxide Including Si) Effect (Samples 1 and 38 to44)

As is shown in tables 3 and 4, contents of not only the fourthsubcomponent (BaCaSiO₃) with respect to 100 moles of the main componentbut composition of the main component and contents of the othersubcomponents in samples 1, 39 and 40 are within the range of theinvention. These samples 1, 39 and 40 show preferable value ofcapacitance change rate, when compared to a sample (e.g. sample 38)comprising less content of the fourth subcomponent than the range of thepresent invention. Further, samples 1, 39 and 40 show denser sinteringwhen compared to a sample (e.g. sample 41) comprising more contents ofthe fourth subcomponent than the range of the present invention.

Also, by referring to samples 42 to 44, when BaSiO₃, CaSiO₃, SiO₂ wereused instead of BaCaSiO₃ as the fourth subcomponent, it was observedthat the same effects as that of BaCaSiO₃ can be obtained.

The Fifth Subcomponent Effect (Samples 1 and 45 to 51)

As is shown in tables 3 and 4, contents of the fifth subcomponent (V₂O₅)with respect to 100 moles of the main component, composition of the maincomponent and contents of the other subcomponents in samples 1, 45 and46 are within the range of the invention. These samples 1, 45 and 46show denser sintering when compared to a sample (e.g. sample 47)comprising more contents of V₂O₅ than the range of the presentinvention.

Further, by referring to samples 48 to 51, when Mo, W, Ta and Nb wereused instead of V as the fifth subcomponent, it was observed that thesame effects as that of V can be obtained.

FIG. 3 of the invention shows capacity temperature characteristic on thebasis of capacitance at 25° C. of sample 1, an example of the presentinvention.

Accordingly sample 1 was found that, within a temperature range of −25to 105° C., a capacitance change rate on the basis of capacitance at 25°C., with respect to a line which shows capacity temperaturecharacteristic on the basis of capacitance at 25° C. and has a slope of−5000 ppm/° C., is within −15 to +5%.

1. A dielectric ceramic composition comprising a main componentexpressed by a general formula:(Ba_(1-x-y)Sr_(x)Ca_(y))_(m)(Ti_(1-z)Zr_(z))O₃, a first subcomponentcomprising Mg oxide, a second subcomponent comprising at least one kindof oxide selected from oxides of Mn and Cr, a third subcomponentcomprising R oxide (note R is selected at least one kind from Y, La Ce,Pr, Nd, Sm, Gd, Tb, Dy, Ho and Yb), and a fourth subcomponent comprisingan oxide including Si, wherein the general formula shows0.20≦x≦0.40,0≦y≦0.20,0≦z≦0.30, and0.950≦m≦1.050, wherein ratios of the respective subcomponents withrespect to 100 moles of said main component are the first subcomponent:0.5 to 5 moles (in terms of element), the second subcomponent: 0.05 to 2moles (in terms of element), the third subcomponent: 1 to 8 moles (interms of element), the fourth subcomponent: 0.5 to 5 moles (in terms ofan oxide or a complex oxide), and within a temperature range of −25 to105° C., a capacitance change rate on the basis of capacitance at 25°C., with respect to slope “a” of a line which shows capacity temperaturecharacteristic on the basis of capacitance at 25° C., is within −15 to+5%, and said slope “a” is −7000 to −3000 ppm/° C.
 2. The dielectricceramic composition as set forth in claim 1, wherein y and z in thegeneral formula of the main component are
 0. 3. The dielectric ceramiccomposition as set forth in claim 1 further comprising a fifthsubcomponent comprising at least one kind of oxide selected from oxidesof V, Mo, W, Ta and Nb, wherein a ratio of the fifth subcomponent withrespect to 100 moles of said main component is 0 to 0.2 moles in termsof each element.
 4. The dielectric ceramic composition as set forth inclaim 2 further comprising a fifth subcomponent comprising at least onekind of oxide selected from oxides of V, Mo, W, Ta and Nb, wherein aratio of the fifth subcomponent with respect to 100 moles of said maincomponent is 0 to 0.2 moles in terms of each element.
 5. An electronicdevice comprising dielectric layers composed of the dielectric ceramiccomposition as set forth in claim
 1. 6. An electronic device comprisingdielectric layers composed of the dielectric ceramic composition as setforth in claim
 2. 7. An electronic device comprising dielectric layerscomposed of the dielectric ceramic composition as set forth in claim 3.8. An electronic device comprising dielectric layers composed of thedielectric ceramic composition as set forth in claim 4.